Medication alone does not always cure mental illness completely. Of late more and more research interest albeit not enough has been directed at nutrition and the role it may play in onset and maintenance of the various mental illness. The mental illnesses discussed in this book are depression, bipolar disorder and schizophrenia. Prevention and treatment of mental illnesses should encompass adequate supplementation of fatty acids, vitamins and minerals through nutrition. This book focusses mostly on vitamin D3 and omega 3 fatty acids and the role they play in the above mentioned mental illnesses. Also briefly discussed are magnesium, folate and zinc. Impaired cognition which is a component of the above 3 disorders is also discussed. Most of the information found in this book is with respect to depressive disorders. This book is suitable for those intending to advance their knowledge about nutrition and some of its effects on mental health.